Fully Autonomous Multiplet Event Detection: Application to Local-Distance Monitoring of Blood Falls Seismicity

Carmichael, Joshua Daniel¹  Carr, Christina²  Pettit, Erin C.² 

[1] Los Alamos National Lab. (LANL), Los Alamos, NM (United States);Univ. of Alaska, Fairbanks, AK (United States)

关键词: Engineering(42);    Environmental Sciences(54);    Geosciences(58);    Mathematics & Computing(97) Icequakes;    correlation detectors;    statistics;    glaciology;    probability;    signal detection;    autonomous signal detection;    brine;    subglacial;   

DOI  :  10.2172/1186035
RP-ID  :  LA-UR--15-24599
PID  :  OSTI ID: 1186035

美国|英语

来源: SciTech Connect

【 摘 要 】

We apply a fully autonomous icequake detection methodology to a single day of high-sample rate (200 Hz) seismic network data recorded from the terminus of Taylor Glacier, ANT that temporally coincided with a brine release episode near Blood Falls (May 13, 2014). We demonstrate a statistically validated procedure to assemble waveforms triggered by icequakes into populations of clusters linked by intra-event waveform similarity. Our processing methodology implements a noise-adaptive power detector coupled with a complete-linkage clustering algorithm and noise-adaptive correlation detector. This detector-chain reveals a population of 20 multiplet sequences that includes ~150 icequakes and produces zero false alarms on the concurrent, diurnally variable noise. Our results are very promising for identifying changes in background seismicity associated with the presence or absence of brine release episodes. We thereby suggest that our methodology could be applied to longer time periods to establish a brine-release monitoring program for Blood Falls that is based on icequake detections.